Common sleep problems in ICU: heart failure and sleep-disordered breathing syndromes.

Ventilation during sleep is under tight metabolic control, and can be destabilized by upper airway obstruction leading to snoring or obstructive apneas, inadequate respiratory pump muscle activity leading to hypoventilation, and central control instability leading to changes in metabolic feedback and loop gain. These three physiologic disturbances can lead to obstructive sleep apnea hypopnea syndrome (OSAHS), hypoventilation syndromes, and periodic breathing. OSAHS places a strain on the cardiac output by virtue of hypoxemia, large negative intrathoracic pressures, and high swings in systemic blood pressure. Periodic breathing, also known as central sleep apnea with Cheyne-Stokes pattern of respiration, is likely to be a product of advanced heart failure.